Quoting from the project's about page: ..After installing an Audioscrobbler Plugin, your computer sends the name of every song you play to the Audioscrobbler Server. With this information, the Audioscrobbler server builds you a 'Musical Profile'. Statistics from your Musical Profile are shown on your Audioscrobbler User Page, available for everyone to view. .. With this information, Audioscrobbler is able to automatically generate suggestions for new songs/artists you might like. These suggestions are based on the same principles as Amazon's "People who bought this also bought X,Y,Z", but because the Audioscrobbler data is what people are actually listening to, the suggestions tend to make more sense than Amazon.

RJ writes:

We've have matched a lot of our artist database to the appropriate MusicBrainz artist id, and we have a simple artist linking system on the way to reduce noise levels so that a direct text-match on artist names will connect most of our artists to musicbrainz.

We're hoping to provide clever playlist generation, and artist similarity data under the same cc license as MB use, which we reckon will be useful to MusicBrainz. We'll also be spewing out RDF for profiles and chart data, containing MB ids. When the webservice is up to it, we'd like to put MB votes/mods on artist(track/album) pages at audioscrobbler.com. Another application of these musical profiles is as a way to serve mods/votes to people based on their musical taste (eg, order the pending moderations list with the most interesting stuff at the top - artists i listen to (and similar artists) should come first)